1. Field of the Invention
The present invention relates to a control unit of a machine tool that controls the machine tool of a machining center or the like, and in particular, relates to a numerical control unit having a screen display switching function following an NC program.
2. Description of the Related Art
Various functions such as positioning and straight feeding are prepared for a numerical control unit that controls machine tools, that is, CNC. An operator executes control so that a machine tool performs a desired operation by creating a machining program that describes a plurality of instructions to execute a function prepared for CNC and executing the machining program. Situations in which the operator wants to check whether the machine tool performs a desired operation based on a created machining program or not arise frequently.
The operation to be checked of the machine tool or machine is represented by a created machining program. A large amount of information representing the operation to be checked of the machine tool or machine may not be displayed on one screen and the operator displays a desired screen by switching the screen to obtain information.
Thus, a plurality of screens representing a machine operation exists and it is necessary to store a method of switching the screen on which desired information is displayed and to perform a switching operation to the screen manually for the operator who checks the created program to display the desired information. Therefore, it is difficult for a novice user to perform the operation and in addition, the number of screen switching operations increases, leading to deterioration of operability.
As disclosed by JP 11-231918 A, an apparatus that saves the operator trouble during execution of a machining program is known. In the apparatus described in JP 11-231918 A, a screen switching command to the specified screen is described in a machining program and the operator is enabled to check the operation of a machine without any operation by the screen being switched based on the command during execution of the machining program.
However, in a configuration that a screen switching operation is instructed in the machining program like the apparatus disclosed by JP 11-231918 A, time and effort for a creator of the machining program to determine the screen to be displayed and to actually write the screen in the program arises, which is inconvenient.